Situation in which progress is impossible, deadlock (7)
I believe the answer is:
impasse
I believe this is a double definition.
'situation in which progress is impossible' is the first definition.
(I've seen this before)
'deadlock' is the second definition.
(I know that deadlock can be written as impasse)
(Other definitions for impasse that I've seen before include "'Deadlock, stalemate (7)'" , "Unpromising situation" , "Maybe gridlock" , "Stand-off, stalemate" , "nothing can be done" .)